M8 x 40mm Carriage Bolts (DIN 603) - Brass Carriage Bolts, also known as Cup Square Bolts, are a strong and durable screw which feature a mushroom shaped head and a square neck below. The large domed head of the Carriage Bolt distributes the force of the fastening over a larger surface area, whilst also offering a smooth aesthetic finish to the end fastening. The square neck of a Carriage Bolt pulls into the wood (or square metal hole) as it is tightened and locks the screw into place. This prevents the Carriage Bolt from turning during fastening and restricts it from loosening. Carriage Bolts are most commonly used with to fasten wood together, however, also can be used with metal or wood\/metal combinations. These Carriage Bolts are made from Brass which offers both high tensile strength and high corrosion resistance. For larger quantities or custom lengths, please email and one of our team will provide you with a quotation. M8 x 40mm Carriage Bolts (DIN 603) - Brass